using Microsoft.Extensions.Logging;
using System.Collections.Concurrent;

namespace DocumentCreationSystem.Services
{
    /// <summary>
    /// 自适应学习引擎
    /// </summary>
    public class AdaptiveLearningEngine
    {
        private readonly ILogger<AdaptiveLearningEngine> _logger;
        private readonly ConcurrentDictionary<string, LearningProfile> _learningProfiles = new();

        public AdaptiveLearningEngine(ILogger<AdaptiveLearningEngine> logger)
        {
            _logger = logger;
        }

        /// <summary>
        /// 学习用户行为
        /// </summary>
        public async Task LearnFromUserBehaviorAsync(string userId, string action, Dictionary<string, object> context)
        {
            try
            {
                _logger.LogDebug($"学习用户行为: {userId} - {action}");
                
                var profile = _learningProfiles.GetOrAdd(userId, _ => new LearningProfile { UserId = userId });
                
                // 记录行为
                profile.BehaviorHistory.Add(new BehaviorRecord
                {
                    Action = action,
                    Context = context,
                    Timestamp = DateTime.Now
                });

                // 更新学习模式
                await UpdateLearningPatternsAsync(profile, action, context);
                
                // 保持最近1000条记录
                if (profile.BehaviorHistory.Count > 1000)
                {
                    profile.BehaviorHistory.RemoveAt(0);
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"学习用户行为失败: {userId} - {action}");
                throw;
            }
        }

        /// <summary>
        /// 获取用户偏好
        /// </summary>
        public async Task<Dictionary<string, object>> GetUserPreferencesAsync(string userId)
        {
            try
            {
                _logger.LogDebug($"获取用户偏好: {userId}");
                
                if (_learningProfiles.TryGetValue(userId, out var profile))
                {
                    return new Dictionary<string, object>(profile.Preferences);
                }
                
                await Task.Delay(1); // 模拟异步操作
                return new Dictionary<string, object>();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"获取用户偏好失败: {userId}");
                throw;
            }
        }

        /// <summary>
        /// 预测用户需求
        /// </summary>
        public async Task<List<string>> PredictUserNeedsAsync(string userId, Dictionary<string, object> currentContext)
        {
            try
            {
                _logger.LogDebug($"预测用户需求: {userId}");
                
                var predictions = new List<string>();
                
                if (_learningProfiles.TryGetValue(userId, out var profile))
                {
                    // 基于历史行为预测
                    var recentActions = profile.BehaviorHistory
                        .Where(b => b.Timestamp > DateTime.Now.AddDays(-7))
                        .GroupBy(b => b.Action)
                        .OrderByDescending(g => g.Count())
                        .Take(5)
                        .Select(g => g.Key)
                        .ToList();

                    predictions.AddRange(recentActions);
                }
                
                // 如果没有足够的历史数据，返回默认预测
                if (!predictions.Any())
                {
                    predictions.AddRange(new[]
                    {
                        "创建新文档",
                        "查看最近文档",
                        "搜索内容",
                        "使用模板",
                        "协作编辑"
                    });
                }
                
                await Task.Delay(1); // 模拟异步操作
                return predictions;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"预测用户需求失败: {userId}");
                throw;
            }
        }

        /// <summary>
        /// 适应用户风格
        /// </summary>
        public async Task<Dictionary<string, object>> AdaptToUserStyleAsync(string userId, string contentType)
        {
            try
            {
                _logger.LogDebug($"适应用户风格: {userId} - {contentType}");
                
                var adaptations = new Dictionary<string, object>();
                
                if (_learningProfiles.TryGetValue(userId, out var profile))
                {
                    // 基于用户偏好调整
                    if (profile.Preferences.ContainsKey("writing_style"))
                    {
                        adaptations["style"] = profile.Preferences["writing_style"];
                    }
                    
                    if (profile.Preferences.ContainsKey("preferred_length"))
                    {
                        adaptations["length"] = profile.Preferences["preferred_length"];
                    }
                    
                    if (profile.Preferences.ContainsKey("complexity_level"))
                    {
                        adaptations["complexity"] = profile.Preferences["complexity_level"];
                    }
                }
                
                // 默认适应设置
                if (!adaptations.Any())
                {
                    adaptations["style"] = "professional";
                    adaptations["length"] = "medium";
                    adaptations["complexity"] = "moderate";
                }
                
                await Task.Delay(1); // 模拟异步操作
                return adaptations;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"适应用户风格失败: {userId} - {contentType}");
                throw;
            }
        }

        /// <summary>
        /// 更新学习模式
        /// </summary>
        private async Task UpdateLearningPatternsAsync(LearningProfile profile, string action, Dictionary<string, object> context)
        {
            try
            {
                // 更新动作频率
                if (!profile.ActionFrequency.ContainsKey(action))
                {
                    profile.ActionFrequency[action] = 0;
                }
                profile.ActionFrequency[action]++;

                // 更新偏好
                if (context.ContainsKey("style"))
                {
                    profile.Preferences["writing_style"] = context["style"];
                }
                
                if (context.ContainsKey("length"))
                {
                    profile.Preferences["preferred_length"] = context["length"];
                }

                // 更新最后学习时间
                profile.LastLearningUpdate = DateTime.Now;
                
                await Task.Delay(1); // 模拟异步操作
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "更新学习模式失败");
                throw;
            }
        }
    }

    /// <summary>
    /// 学习档案
    /// </summary>
    public class LearningProfile
    {
        public string UserId { get; set; } = string.Empty;
        public List<BehaviorRecord> BehaviorHistory { get; set; } = new();
        public Dictionary<string, object> Preferences { get; set; } = new();
        public Dictionary<string, int> ActionFrequency { get; set; } = new();
        public DateTime CreatedAt { get; set; } = DateTime.Now;
        public DateTime LastLearningUpdate { get; set; } = DateTime.Now;
    }

    /// <summary>
    /// 行为记录
    /// </summary>
    public class BehaviorRecord
    {
        public string Action { get; set; } = string.Empty;
        public Dictionary<string, object> Context { get; set; } = new();
        public DateTime Timestamp { get; set; }
    }
}
